The present invention relates to the photoprocessing and/or photofinishing field. More particularly, the present invention relates to a method and apparatus for applying a solution of a predetermined viscosity to photosensitive material, preferably processed photosensitive material, to form a protective overcoat on at least one surface of the photosensitive material.
In order to apply a protective coating to an emulsion surface of a photosensitive material, control over the thickness, uniformity and lay down amount of the coating being applied is needed in order to provide for adequate protection against moisture and scratches. The control is needed for several reasons: 1) the protective coating must be applied in a manner that insures that the surface is uniformly coated so that the coating can provide adequate protection to the entire surface; 2) that thickness of the coating must be controlled because if the coating is too thick, it could cause cracking, due to non-uniform drying; 3) a thick coating could dull the surface and the underlying image of photographic print; and 4) the coating solutions can be of different viscosities.
U.S. Pat. No. 5,318,804 discloses a coater for applying a liquid onto a surface of a moving object. In the coater of U.S. Pat. No. 5,318,804, a coating liquid is applied onto a coating roll which transports the coating liquid onto a supporter that is positioned on a backup roll. A drawback of the coater of U.S. Pat. No. 5,318,804 is that no provision is made for assuring that the coating liquid is guided to and kept at a nip portion between the rolls, so as to provide for an even application of coating liquid and to maintain the rolls in a wet state.
U.S. Pat. No. 5,690,999 discloses a coating device for the coating of a size-press roll, paper or board. This patent discloses a revolving coating bar which rests against a press roller. Like the arrangement shown in U.S. Pat. No. 5,318,804, the arrangement of U.S. Pat. No. 5,690,999 also does not provide for a mechanism for guiding and keeping coating liquid at a vicinity of a nip portion between rollers, so as to assure a uniform application of coating liquid and to maintain the rolls in a wet state.
The present invention provides for a novel method and apparatus which can apply a solution of a predetermined viscosity to the surface of photosensitive material, preferably processed photosensitive material, prior to the final drying of the material to form a protective overcoat. In the present invention, the solution is applied a manner that allows the solution to be uniformly applied to the surface of the photosensitive material at a specific thickness.
With the method and apparatus of the present invention, a solution of predetermined viscosity is guided to a vicinity of a nip portion between two drive rollers by a solution supply guide member. The arrangement of the present invention assures that at least an upper roller of the drive rollers is maintained wet with the solution, and also provides for the formation of a bead of solution in a vicinity of the nip portion, so as to promote a consistent and even application of solution to photosensitive material that is guided between the drive rollers.
The present invention relates to a method of applying at least one solution of a predetermined viscosity to photosensitive material. The method comprises the steps of providing a solution supply guide member at a position relative to first and second rollers, such that one end of the guide member extends toward a nip portion between the first and second rollers; supplying a solution of a predetermined viscosity onto the guide member so that the solution flows along the guide member and is guided toward the nip portion between the first and second rollers, so as to form at least one bead of the solution; and conveying a photosensitive material toward the nip portion, such that the solution is applied to the surface of a photosensitive material.
The present invention also relates to an apparatus for applying at least one solution of a predetermined viscosity to photosensitive material. The apparatus comprises first and second rollers rotatably mounted in a tank so as to define a nip portion therebetween; a solution supply guide member positioned relative to the first and second rollers such that one end of the guide member extends toward the nip portion; and a solution supply port for introducing a solution of a predetermined viscosity onto the guide member, such that the solution flows along the guide member and is guided toward the nip portion to form at least one bead of the solution.
The present invention also relates to a method of applying at least one solution of a predetermined viscosity to photosensitive material which comprises the steps of providing a solution supply guide member at a position relative to first and second rollers so that one end of the guide member extends toward a nip portion between the first and second rollers; supplying a solution of a predetermined viscosity onto one of the first and second rollers, such that the solution flows along an outer peripheral surface of the one of the first and second rollers in a direction toward the one end of the guide member, and is guided by the guide member toward the nip portion, wherein the solution guided by the guide member toward the nip portion forms a bead in a vicinity of the nip portion; and conveying a photosensitive material toward the bead and into the nip portion, such that the solution is applied to the photosensitive material.
The present invention further relates to an apparatus for applying at least one solution of a predetermined viscosity to photosensitive material which comprises first and second rollers rotatably mounted in a tank so as to define a nip portion therebetween; a solution supply guide member positioned relative to the first and second rollers such that the one end of the guide member extends toward the nip portion; and a solution supply port for introducing solution of a predetermined viscosity onto one of the first and second rollers, such that the solution flows along an outer peripheral surface of the one of the first and second rollers in a direction toward the one end of the guide member, wherein the guide member guides the solution toward the nip portion and the solution forms a bead in a vicinity of the nip portion.
The present invention also relates to an apparatus for applying at least one solution of a predetermined viscosity to photosensitive material which comprises first and second rollers mounted in a tank so as to define a nip portion therebetween; a solution supply guide member positioned relative to the first and second rollers such that one end of the guide member extends toward the nip portion; and a solution supply port for introducing a solution of a predetermined viscosity into the tank, such that the guide member guides the solution toward the nip portion and the solution forms a bead in a vicinity of the nip portion.
The present invention also relates to a photoprocessing system which comprises a processor for processing photosensitive material; and a coating apparatus for applying at least one solution of a predetermined viscosity to the processed photosensitive material. The coating apparatus includes first and second rollers mounted in a tank so as to define a nip portion therebetween; a solution supply guide member positioned relative to the first and second rollers such that one end of the guide member extends toward the nip portion; and a solution supply port for introducing a solution of a predetermined viscosity into the tank, such that the guide member guides the solution toward the nip portion and the solution forms a bead in a vicinity of the nip portion.